1. Field of the Invention
This invention relates to the field of vascular surgery, and more specifically, is directed to an apparatus and method for repairing a vascular aneurysm.
3. Art Background
The prior art method of treating a vascular aneurysm and some other vascular problems has been to excise the aneurytic tissue and replace it with a synthetic graft or a graft from another section of the body. This surgery has been extremely risky, and a high mortality rate has been observed, primarily because the condition of the patients undergoing the surgery is generally weak.
In recent years, a number of companies have devised new methods and devices for treating aneurysms and other vascular disease in which the blood vessels are damaged and unable to safely retain the blood passing therethrough. The devices are comprised of vascular prosthetic graft with a connecting means of some type for connecting the prosthesis to the damaged blood vessel at a position displaced from the aneurysm or damage, the prosthesis being sized to fit within the blood vessel, so that the graft permits the blood to travel through the damaged vessel without applying any pressure to the damaged vessel at the point of damage.
U.S. Pat. No. 4,140,126 discloses one such prior art device and method for repairing an aneurysm. This device is positioned in a vessel in a collapsed form, and is then expanded and then attached to the inside of the wall of the vessel with hooks which extend when the device is expanded from its collapsed form.
U.S. Pat. No. 4,787,899 discloses an artificial intraluminal graft with u-shaped staples near the end for securing the graft to the vessel. U.S. Pat. No. 5,104,399, which is a continuation in part of the '899 patent, discloses a generally cylindrical graft with a staple assembly in a v-shaped lattice work which is assembled into its operational configuration by the inflation of a balloon in the interior of the assembly.
U.S. Pat. No. 5,219,355 discloses an intraluminal prosthesis for repairing aneurysms which utilizes a catheter having two inflatable balloons, one near each end of the prosthesis, for securing the prosthesis in place in the vessel.
While the retention systems appear to be effective in retaining the grafts in the vessel, over time, it is anticipated, and there have been some recent reports that the vessel wall where the graft connects thereto becomes weakened, and a subsequent aneurysm may occur at that position. As an additional factor, the penetration into the wall by the staples causes some fibrosis, and the tissue buildup at the location of the connection can cause some blood flow restriction which would increase the pressure on the vessel walls at the site of contact between the blood vessel and the graft. This condition may also increase the risk of a subsequent aneurysm.
The present invention is designed to operate in conjunction with a number of various retention systems for retaining a vascular graft in a vessel by attaching the graft to the interior wall of the vessel, without the risk. Each of these has certain deficiencies which are described below, which deficiencies are resolved by the present invention.